Coral–algal phase shifts on coral reefs: Ecological and environmental aspects

Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil

“…Therefore, the main macroalgae recorded in this study could avoid the occurrence of molluscan herbivores at Maracajaú by chemical and morphological defenses, although more studies are needed to investigate this process. Moreover, the great cover of fleshy algae on the reef could prevent the growth and settlement of reef building corals (Done, 1992;Hughes, 1994;McCook, 1999, McCook et al, 2001McManus and Polsenberg, 2004), which could indirectly influence the low molluscan richness on Maracajaú's reef.…”

Conditions of coral communities in the Gulf of Thailand: a decade after the 1998 severe bleaching event

“…A long term monitoring program should be effectively implemented at unhealthy communities in the Gulf of Thailand in order to examine degradation trends or natu ral recovery processes (Cooper et al 2009;Sutthacheep et al 2009). Degradation of coral reefs is frequently associated with changes in community structure where macroalgae become the dominant benthic component (Done 1992;McManus and Polsenberg 2004;Norstrom (Sudara et al 1994). The impact of climate change, especially thermal stress related coral bleaching on coral reefs in the Pacific and other parts of the world has been well documented (Obura 2005;Baker et al 2008;Smith et al 2008;Wilkinson 2008).…”

Can strong consumer and producer effects be reconciled to better forecast ‘catastrophic’ phase-shifts in marine ecosystems?

“…Too much emphasis appears to have been placed on the ubiquity of certain kinds of phase-shifts (as reviewed by Bruno et al, 2009 for coral-seaweed shifts) or one kind of indirect effect at the expense of alternate causes (reviews by Heck and Valentine 2007 for seagrasses; Foster and Schiel, 2010 for kelp forests). Nevertheless, the repeated observation of phase-shifts in coral (review by McManus and Polsenberg, 2004), kelp (review by Airoldi et al, 2008) and seagrass systems (Eklof et al, 2008) means that they will continue to represent opportunities for the study of profound ecological effects.…”